This invention relates to monitoring apparatus and more particularly to a method and apparatus for indicating at a distance the onset of parturition in animals.
Present devices for monitoring parturition include closed circuit television systems, in which a person continuously watches a television screen for signs of parturition; radio monitoring systems, in which a person must continuously listen to a radio receiver for sounds of parturition; transmitting apparatus strapped around the girth of the pre-parturient animal, which is triggered by the female assuming a predetermined position during labor; an apparatus in which a pregnant sow is placed so that the first piglet born lands on a plate causing a bell to ring; an elastic belt fitted around the abdomen of a pregnant woman and connected to an X-Y recorder to record the pattern of uterine contractions during labor; and electrical apparatus connected to the lips of the cervix for providing a continuous indication at the site of the patient of the dilation of the cervix prior to the actual birth of an infant. Representative patents in which the latter two techniques are disclosed are U.S. Pat. Nos. 3,520,294 and 3,273,559.
A user of any of the above apparatus will obtain an accurate indication of the onset of parturition only if he continually monitors the apparatus or the animal assumes the predetermined position while giving birth. Using the closed circuit television system as an example, if the user happens to doze off while watching the monitor, the birth might occur while the observer is asleep. Additionally, most of the devices described above require that the pregnant animal be at a specific place. The closed circuit television system, for example, requires that the animal be within the field of view of the camera. The majority of the other systems require that the animal by physically in or attached to the rest of the apparatus during monitoring. Clearly these constraints are undesirable in the case of a large animal, such as a pregnant cow or mare, if she is to be monitored for any length of time.